New Biosensors Will Monitor Physiological Signs

Researchers at the University of Arkansas in Fayetteville are testing possible applications of different biosensors – hoping to bring them into use in the health-care industry. The sensors can be applied onto special fabrics with wireless technology, continuously monitoring the patient’s physiological signs providing real-time results.
Taeksoo Ji, left, and Soyoun Jung, University of Arkansas.

Taeksoo Ji, left, and Soyoun Jung
(Credit: University of Arkansas).

The research, conducted by Taeksoo Ji, Assistant Professor of Electrical Engineering, and by Soyoun Jung, an electrical engineering graduate student, was held under the direction of Vijay Varadan – Distinguished Professor of Electrical Engineering. The researchers are currently testing two different biosensors – one monitoring respiration rates and the other monitoring body temperature. The temperature sensor uses a thin-film transistor, which deposits thin-film semiconductors on flexible polymeric substrates. This transistor enables a linear translation between the temperature changes measured and the resulting electrical current. The strain sensor developed to measure the respiration rate was designed to sense a physiological strain, such as breathing, that causes a mechanical deformation of the sensor. The sensor then translates this influence into an electrical current and finally receives the result by measuring the electrical current’s resistance. The scientists used carbon nanotubes in order to achieve high sensitivity levels in both sensors. 

If the  research is successful it may provide a practical solution to patients whose vital signs need to be continuously monitored. These biosensors can be easily integrated into clothing, such as undershirts, and using a wireless system this data could be transmitted in real-time to the hospital’s computer system or even directly to the physician’s mobile phone. “We’re trying to move diagnostic testing out of the laboratory and directly to the patient. Although there has been some success at this effort over the past decade, traditional materials are not suitable for manufacturing low-cost, large-area sensor devices. The advantages of organic semiconductors will allow manufacturers to produce devices that are light, flexible and easily integrated into biomedical applications such as smart vests and fabrics.”, said Taeksoo Ji.   

One of the main problems with today’s traditional measurement devices is the inaccuracy caused by a weak skin-sensor contact. The use of biological materials can significantly improve the results of measurements as it reduces the external electrical interference, thus increasing the sensitivity. This method of “wireless” monitoring can also enable patients to be under medical supervision even when they are not at the hospital, without taking unnecessary risks. Moreover, in this way patients can undergo long-term monitoring, which is impossible to achieve using conventional devices. 

The potential of biosensors has been studied by various teams worldwide: “Wireless Project” – a research recently conducted in Finland, was aimed at developing wireless sensor technology especially for ambulatory and implantable human physiological applications. Led by Jukka Lekkala, a Professor at the Institute of Measurement and Information Technology at Tampere University of Technology, the research was funded by the Academy of Finland. The subcutaneous biosensors developed in the framework of this research, are able to provide more accurate prediction of changes in a patient’s condition.

More information about the study at the University of Arkansas can be found here.